Excavating machine



June 5, 1962 A. J. D] LIDDO ETAL 3,037,307

EXCAVATING MACHINE 2 Sheets-Sheet 1 Filed Nov. 18, 1959 INVENIORS 0 J. DILIDDO mm Hunnzw Hamzv L. MEYER June 1962 A. J. D! LIDDO ETAL 3,037,307

EXCAVATING MACHINE 2 Sheets-Sheet 2 Filed NOV. 18, 1959 INVENIORS FNDREW J. D: LIDDO m HENRY L. MEYER Sb E! HMO/122W 5M m, law,

nite States Patent lno Filed Nov. 18, 1959, Ser. No. 853,793 6 Claims. (Cl. 37-97) This invention relates in general to excavating machines and more particularly to a liquid-type grade indicator for such a machine for readily establishing and maintaining a predetermined surface of grade for the excavating unit of the machine, such as the bottom plane of a trench or the like to be excavated,

In excavating work, it is often necessary to dig a trench or ditch to accurate grade and often times such digging is accomplished over relatively rough or uneven terrain. The latter necessity for accuracy in grade is especially true for excavating work dealing with the laying of conduits for sewer or water lines and the like.

Various arrangements are known in the art for establishing the grade or depth of digging of the digging unit of an excavating machine, but such prior art arrangements are either excessively high in cost or do not operate effectively to maintain predetermined grade, and especially over rough terrain, wherein the machine may be tilted endwise or fore and aft from a true horizontal position and/ or laterally or sidewise from a true vertically upright position.

The present invention provides 'a simple and economical liquid-type grade arrangement for an excavating machine for readily enabling the machine operator to maintain the desired grade or depth for the excavation or trench, and one which will operate effectively irrespective of the general roughness of the terrain over which the machine passes during excavating operations.

Accordingly an object of the invention is to provide an improved liquid-type grade indicator for an excavating machine.

Another object of the invention is to provide a grade indicator of the latter mentioned type which will operate effectively to establish an accurate grade for a trench or excavation irrespective of relatively rough terrain over which the excavating machine travels.

Another object of the invention is to provide a liquidtype grade indicator arrangement which is adjustably mounted on an excavating machine to enable greater flexibility of use thereof over a wider range of digging depths and under various digging conditions.

A still further object of the invention is to provide an excavating machine having a simplified and effective liquid-type grade indicator arrangement embodied therein.

Other objects and advantages of the invention will be apparent from the following description taken in conjunction with the accompanying drawings wherein:

FIG. 1 is a side elevational view of an excavating machine embodying the instant invention;

FIG. 2 is a fragmentary, top plan, diagrammatic view of the digging unit of the excavating machine of FIG. 1, illustrating the location of the supply tank of liquid for the liquid-grade indicator, and their positions on the supporting frame or boom of the digging unit of the machine;

FIG. 3 is a fragmentary, generally perspective view of the sight tube of the grade indicator and its supporting structure as mounted on the excavating machine;

FIG, 4 is a diagrammatic illustration of the sighting by the machine operator over the top level of the liquid in the sight tube into alignment with a sight or target stake which is disposed along the path of the excavation to be dug, to thus provide for maintaining the grade of the excavating unit during excavating operations.

3,037,307 Patented June 5, 1962 Referring now to the drawings and especially to FIG. 1 thereof, there is shown a trenching machine of the well known wheel type embodying the instant invention. Such an excavating or trenching machine broadly comprises a main frame 10 supported on suitable tractor treads 12, a main power plant or internal combustion engine 14 supported on the forward end of frame 10, a structure 16 for supporting a vertically movable boom structure 18, an excavating wheel or unit 20 rotatably mounted on boom 18 by means of frame and wheel arrangement 22 and 22a, and drivingly connected to motor unit 14 of the machine as by means of the chain and sprocket arrangement generally referred to by reference number 24, and a transversely extending discharge conveyor 26 which is adapted to receive material from digging unit 18 and carry it to either side of the machine.

Boom structure 18 is pivotally mounted as at 28 for movement in a generally vertical plane, and may be raised and lowered on structure16 by means of carriage elements 29 to which the boom frame is pivotally connected. Carriage elements 29 and attached boom 18 are actuated by cable and pulley systems 30, 31, actuated by winding drums 32 and 34 mounted on the machine frame and in a manner well known in the art. It will be understood of course that other structural arrangements and systems could be utilized for controlling the movement of the boom 18 and associated digging unit 20 without departing from the scope of the invention.

The controls for operating the various components of the machine, including the aforementioned main power plant 14, the winding drums 32, 34, the digging unit 20, etc., may include the levers36, 37, 38, 39 as shown, with the latter being localized in a particular area on the machine and in the vicinity of the machine operators work station 40, for convenient access by the machine operator.

In accordance with the invention, a liquid-type grade indicator mechanism is mounted on the machine for use by the machine operator in maintaining the desired grade or depth of the trench to be dug by the machine. This grade indicator mechanism takes the form of at least one pair of tanks or reservoirs, adapted to contain liquid, such as colored water, to which may be added a quantity of anti-freeze or the like to prevent freezing thereof in cold weather. Such tanks are Vented to the atmosphere preferably at the upper ends thereof. One (42) of the tanks may be mounted on one side of the digging unit frame 18 forwardly of the discharge conveyor 26, and the other (44) of the tanks may be mounted on the opposite side of the frame 18 an equal distance rearwardly of the discharge conveyor. In other words, the reservoir tanks 42 and 44 are spaced equal distances from both the longitudinal vertical and transverse vertical center planes of the boom frame and associated digging unit of the machine. The supply tanks 42 and 44 are connected to one another at the bottoms thereof, as by connecting line 46 (FIG. 2). A feed line 48 extends from one of the tanks, such as tank 42, along the machine chassis to the forward end thereof, where it is connected to an open topped, transparent sight tube 50 formed of plastic, glass or the like. Various portions, such as 48aand 48b of the feed line 48 should be of relatively flexible material, and may be looped, as shown, for permitting adjustment of the boom 18 and of the sight tube 50 with respect to the machine chassis, as will be hereinafter described.

Sight tube 50 is secured as by means of bracket elements 52 to a vertical support member or rod 54 which in turn is adjustably attached, as by means of threaded bolt and bracket member 56 to a weight or base portion 58. Base 58 has a supporting or knife edge portion 58a which is mounted in freely pivotal relation on a generally horizontal arm element 62 and preferably in a locating groove or depression adjacent the outer end of the horizontal arm element 62. Arm 62 in turn is adjustably connected to the machine chassis, as by means of wing bolt and bracket 64. It will be seen therefore that the weight of base portion 58 is supported in pendulum fashion adjacent the outer end of arm 62, base 58 being of sutficient weight and being so constructed to maintain the rod 54 and attached sight tube 50 in vertical position irrespective of the position of the machine proper. It will also be seen that the tube 59 may be readily adjusted vertically by adjustment of the wing bolt 56 and thus adjustment of the support rod 54, and may be adjusted laterally of the machine chassis by adjustment of arm 62, to thereby provide for the use of the grade-indicator over a wide range of digging depths. A hand operated valve 61 (FIG. 1) may be provided in feed line 48 for controlling the flow of liquid to tube 50. While the sight tube 50 has been illustrated in FIG. 1 forwardly of the operators work station 40, for forward sighting by the workman, it will be understood that the sight tube could be just as readily mounted rearwardly of the work station 40 and on the machine chassis, for rearward sighting by the operator.

Operation of the grade indicator mechanism is as follows:

Grade stakes 70 or other reference markers are disposed along the path which the trench is to extend, such reference markers being preferably 50 to 100 feet apart, and the sight or target portions 78 thereof are adjusted to the proper predetermined height to give the desired grade and depth to the bottom of a trench when the vertical disposition of the digging unit of the machine is correlated with such target portions. The supply tanks are filled as aforementioned with readily visible liquid to a known level above the bottommost extremity of the digging wheel 20. When the digging wheel has dug itself to the approximate desired depth of trench below ground level, the control valve 61 is opened and thus the level of the liquid in the tanks 42 and 44 is reflected in the height that the liquid rises to in the sight tube 50. The machine operator by visually sighting as at A (FIG. 4) over the top of the column of water in the tube and maintaining such top level of the column of liquid in the tube in alignment with the target portions 78 of the sight stakes by proper vertical plane positioning of the digging unit 20, maintains a desired grade or depth of trench. It will be seen that the liquid level in the sight tube will always indicate a known distance above the bottom of the trench and that an accurate liquid level in the tube will always be obtained even if the machine is operating over rough terrain. It will also be seen that the sight tube 50 will always be maintained in perpendicular position with respect to the horizontal irrespective of the fore and aft, or sidewise, tilting of the machine and digging unit, due to the pendulum-like mounting arrangement for the sight tube, thereby maintaining the top surface of the liquid in the tube always horizontal for ready alignment with the target portions of the sight stakes, and therefore accurately maintaining the predetermined grade and/or depth of the excavation being dug. By providing for adjustment of the sight tube vertically with respect to the machine chassis, use of a shorter sight tube over a wider range of digging depths is possible. Provision for adjustment of the sight tube toward and away from the side of the machine allows the operator t9 sight over the fixed sight or grade stakes even while cutting a curved trench.

From the foregoing description and accompanying drawings, it will be seen that the invention provides an excavating machine embodying a novel liquid-type grade indicator for readily establishing predetermined surfaces of grade for the excavating unit of the machine. It will also be seen that the invention provides a grade indicator of the above type which can be readily embodied in new excavating machines or in existing machines, and one which is adjustably mounted on the machine for greatly increasing the usability thereof under varied operating conditions.

The terms and expressions which have been employed are used as terms of description and not of limitation and there is no intention in the use of such terms and expressions of excluding any equivalents of any of the features described or shown, or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed.

We claim:

1. In a mobile excavating machine, a frame, a generally horizontally extending boom carried by said frame for positioning movement in a generally vertical plane, an endless movable digging unit carried by said boom and depending therefrom, and a liquid-type grade indicator carried by said machine, said grade indicator comprising reservoir means carried by said boom in fixed relation thereto for movement therewith and adapted to contain a quantity of liquid at a predetermined level above the bottom-most extremity of said digging unit, said reservoir means comprising at least one pair of tanks, said tanks being disposed on opposite sides of said digging unit at substantially equal distances from the longitudinal vertical center plane of said unit and on opposite sides of and equal distances from the transverse vertical center plane of said unit, conduit means providing fluid communication between said tanks, a sight tube mounted on said frame remote from said reservoir means, means for maintaining said sight tube in a substantially vertically oriented position irrespective of sidewise and fore-andaft tilting movement of the machine with respect to the horizontal, and conduit means connecting said sight tube to one of said tanks whereby the level to which liquid from said reservoir means will rise in said sight tube will correspond to the mean distance between the level of the liquid in said tanks to the bottom-most extremity of said digging unit irrespective of the movement of said boom.

2. In a mobile excavating machine, a frame, an operators work station on said frame, a. generally horizontally extending boom carried by said frame for positioning movement in a generally vertical plane, a wheel type digging unit rotatably carried by said boom and depending therefrom, a discharge conveyor mounted on said boom and extending transversely through said digging unit along the transverse vertical center plane thereof, for receiving dug material from said digging unit and discharging it to a side of said frame, and a liquid type grade indicator carried by said machine, said grade indicator comprising reservoir means mounted on said boom in fixed relation thereto for movement therewith and adapted to contain a quantity of liquid at a predetermined level above the bottom-most extremity of said digging unit, said reservoir means comprising at least one pair of elongated upright tanks, said tanks being mounted on said boom on opposite sides of said digging unit at substantially equal distances from the longitudinal vertical center plane of said unit and on opposite sides of and substantially equal distances from the transverse vertical center plane of said unit, means connecting said tanks to gether for fiuid communicating relation, a sight tube, means mounting said sight tube on said frame in the vicinity of the operators work station and maintaining said sight tube in a substantially vertically oriented position irrespective of sidewise and fore-.and-aft tilting movement of the machine with respect to the horizontal, said last mentioned means comprising a base weight mounted in pendulum fashion on said frame and rod means extending upwardly from said base weight above the connection of said base weight to said frame, said sight tube being attached to said rod means, and conduit means connecting said reservoir means to said sight tube, whereby the level to which liquid from said reservoir means will rise in the sight tube will correspond to the mean distance between the level of liquid in said tanks to the bottommost extremity of said digging unit irrespective of the movement of said boom.

3. In an excavating machine in accordance with claim 2 including valve means disposed adjacent said operators work station and coacting with said conduit means for selectively controlling liquid communication between said sight tube and said reservoir means.

4. In a mobile excavating machine a frame, traction means for supporting said frame for movement along the ground, a generally horizontally extending boom carried by said frame at the rearward end thereof for positioning movement in a substantially vertical plane, said positioning movement including both vertical linear movement and fore-and-aft tilting movement, a wheel type digging unit carried by the said boom and mounted for rotary digging movement in a generally vertical plane, a discharge conveyor carried by said boom and extending transversely through said digging unit and in general alignment with the transverse vertical center plane of said digging unit for receiving dug material from said digging unit and discharging, it to a side of said frame, and a liquid-type grade indicator carried by said machine, said grade indicator comprising at least one pair of reservoir tanks, said tanks being mounted in fixed relation on said boom adjacent to and equal distances from opposite sides of said digging unit, one of said tanks being mounted forwardly of said conveyor and the other of said tanks being mounted an equal distance rearwardly of said conveyor, conduit means providing communication between said tanks, a generally vertically extending sight tube mounted on said frame, means for maintaining said sight tube in generally vertical orientation irrespective of the tilting movement of the machine both fore-andaft and sideways with respect to the horizontal, and conduit means connecting one of said tanks to said si-ght tube, said tanks being adapted to contain a quantity of liquid to a predetermined level above the bottommost extremity of said digging unit, such'liquid being adapted to rise in said sight tube to a level corresponding to the mean distance between the level of the liquid in said tanks to the bottommost extremity of said digging unit irrespective of the movement of said boom.

5. In a mobile excavating machine in accordance with claim 4 wherein said means for maintaining said sight tube in a generally vertically oriented position comprises an arm extending laterally of said frame, a base Weight mounted in pendulum fashion on said arm, said base weight supporting an extensible upright rod thereon, said sight tube being secured to said rod above the connection of said base Weight to said arm, and means for locking said rod in selected position.

6. In a mobile excavating machine in accordance with claim 5 wherein said arm is: adjustably mounted on said frame for linear movement laterally thereof, and means for locking said arm in selected position.

References Cited in the file of this patent UNITED STATES PATENTS 277,037 Le Grande May 8, 1883 532,949 Darragh Jan. 22, 1895 1,099,385 Linga June 9, 1914 1,369,235 Funk Feb. 22, 1921 2,109,044 Grieve Feb. 22, 1938 2,552,964 Hansen et al. May 15, 1951 2,873,541 Eliason Feb. 17, 1959 FOREIGN PATENTS 6,742 Great Britain of 1834 OTHER REFERENCES Moving the Earth, H. L. Nichols, published by D. Van Nostrand Co., April 1954. Pages 14-44 and 1445. 

